Effects of Outliers

A value that is much higher or much lower than the other values in a set of data.

• Outlier
• Box Plot
• Range
• Histogram

The data set below has an outlier of 42.

2, 5, 12, 15, 19, 4, 6, 11, 16, 18, 12, 12, 42

What effect does removing the outlier have on the data?

• The mean will decrease

• The median will decrease

• The mean will increase

• The median will increase

Gabriella’s quiz grades are shown below.
88, 92, 92, 96, 98
Gabriella scored a 20 on her sixth quiz. What effect does this score have?

• The low score causes the median to increase.
• The low score causes the median to decrease.
• The low score causes the mean to increase.
• The low score causes the mean to decrease.

Given the following data set
6, 9, 12, 14, 7, 9, 6, 8, 25, 12, 14
What is the mean of the data set without the outlier(s)?

• 9.2
• 9.7
• 11.1
• 12.4

The data below represent the ages of several people in a class.What effect does Mr. Smith’s age have on the data set?

• Mr. Smith’s age increases the mode of the data.
• Mr. Smith’s age decreases the mean of the data.
• Mr. Smith’s age increases the mean of the data.
• Mr. Smith’s age increases the median of the data.

The salaries of the employees in a company are listed below:

$28,000 $45,000

$31,000 $42,000

$55,000 $72,000

$88,000 $53,000

If $88,000 was found to be an outlier, which salary would be the new maximum?

• $55,000

• $28,000

• $88,000

• $72,000